<?php
/*
 Copyright 2006 Iván Montes

 This file is part of FLV tools for PHP (FLV4PHP from now on).

 FLV4PHP is free software; you can redistribute it and/or modify it under the 
 terms of the GNU General Public License as published by the Free Software 
 Foundation; either version 2 of the License, or (at your option) any later 
 version.

 FLV4PHP is distributed in the hope that it will be useful, but WITHOUT ANY 
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR 
 A PARTICULAR PURPOSE. See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with 
 FLV4PHP; if not, write to the Free Software Foundation, Inc., 51 Franklin 
 Street, Fifth Floor, Boston, MA 02110-1301, USA
*/

include_once FLV_INCLUDE_PATH . 'Tag/Generic.php';
include_once FLV_INCLUDE_PATH . 'Util/BitStreamReader.php';

class FLV_Tag_Video extends FLV_Tag_Generic {

    const CODEC_SORENSON_H263 = 0x02;
    const CODEC_SORENSON = 0x03;
    const CODEC_ON2_VP6 = 0x04;
    const CODEC_ON2_VP6ALPHA = 0x05;
    const CODEC_SCREENVIDEO_2 = 0x06;
        
    const FRAME_KEYFRAME = 0x01;
    const FRAME_INTERFRAME = 0x02;
    const FRAME_DISPENSABLE = 0x03;

    public $codec;
    public $frametype;
    public $width;
    public $height;
    
    
    function analyze()        
    {
        $bits = new FLV_Util_BitStreamReader( $this->body );

        $this->frametype = $bits->getInt( 4 );
        
        $this->codec = $bits->getInt(4); 
        switch ($this->codec)
        {
            case self::CODEC_SORENSON_H263 :
            
                //skip video packet header
                $bits->seek( 17+5+8, SEEK_CUR );

                switch ($bits->getInt(3))
                {
                    case 0x00:
                        $this->width = $bits->getInt(8);
                        $this->height = $bits->getInt(8);
                    break;
                    case 0x01:
                        $this->width = $bits->getInt(16);
                        $this->height = $bits->getInt(16);
                    break;
                    case 0x02: //CIF
                        $this->width = 352;
                        $this->height = 288;
                    break;
                    case 0x03: //QCIF
                        $this->width = 176;
                        $this->height = 155;
                    break;
                    case 0x04: //SQCIF
                        $this->width = 128;
                        $this->height = 96;
                    break;
                    case 0x05: 
                        $this->width = 320;
                        $this->height = 240;
                    break;
                    case 0x06: 
                        $this->width = 160;
                        $this->height = 120;
                    break;
                }
            break;
            
            /* TODO: not tested */
            case self::CODEC_SCREENVIDEO_2 :
            
                $this->width = $bits->getInt(12);
                $this->height = $bits->getInt(12);              
                
            break;
            
            // format layout taken from libavcodec project (http://ffmpeg.mplayerhq.hu/)
            case self::CODEC_ON2_VP6 :
            case self::CODEC_ON2_VP6ALPHA :
                
                $adjW = $bits->getInt(4);
                $adjH = $bits->getInt(4);
                $mode = $bits->getInt(1);
                if ($mode === 0)
                {
                    $bits->seek(15, SEEK_CUR);
                    $this->height = $bits->getInt(8) * 16 - $adjH;
                    $this->width = $bits->getInt(8) * 16 - $adjW;
                }
                
             break;
        }
    }
}

?>